|Publication number||US7040773 B1|
|Application number||US 11/015,942|
|Publication date||May 9, 2006|
|Filing date||Dec 17, 2004|
|Priority date||Dec 22, 2003|
|Publication number||015942, 11015942, US 7040773 B1, US 7040773B1, US-B1-7040773, US7040773 B1, US7040773B1|
|Inventors||Robert Zincone, James V. Masi|
|Original Assignee||Robert Zincone, Masi James V|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (9), Referenced by (6), Classifications (10), Legal Events (3)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application claims priority on U.S. Provisional Patent Application No. 60/531,773, filed Dec. 22, 2003, which is herein incorporated by reference in its entirety.
The present invention relates in general to a self contained traffic signal or light, and more particularly to a traffic light using natural light in combination with light emitting diodes to illuminate the signal lights.
Traffic lights are routinely used to control traffic along roadways and intersections. These traffic lights are often required to be powered by line voltage supplied by overhead wires. These traffic lights, while individually not requiring substantial amounts of power to illuminate the individual traffic signals, in total relatively large amounts of electrical power is used in the illumination of the traffic lights. Recently, there has been much development in traffic lights utilizing light emitting diodes rather than other forms of incandescent illumination. While the light emitting diodes are relatively efficient and have a relatively long life, during daylight hours it is often difficult for a light emitting diode to generate sufficient illumination to be clearly visible. There have been many efforts to aid in making more visible the illumination from a traffic signal utilizing light emitting diodes.
One such light emitting diode signal light is disclosed in U.S. Pat. No. 6,599,002 issuing to Hsieh et al on Jul. 29, 2003 and entitled “LED Signal Light”. Therein disclosed is a light emitting diode signal light using a plurality of lens cells. The plurality of lens cells is used to redistribute the light in vertical and horizontal directions and adjust orientation of light to the specified illumination areas.
Another effort to enhance light emitting diode illumination, which may be used in a traffic light, is disclosed in U.S. Pat. No. 5,174,649 issuing to Alston on Dec. 29, 1992 and entitled “LED Lamp Including Refractive Lens Element”. Therein disclosed are a plurality of facets that allow a large area on the lamp to appear to viewers to be uniformly illuminated.
In addition to the problems associated with the use of LED lights, there is also a problem of power interruptions or reduced line voltage which reduces the light emitting diode output. One solution to reduced light emitting diode illumination caused by interruptions in line voltage is disclosed in U.S. Pat. No. 5,457,450 issuing to Deese et al on Oct. 10, 1995 and entitled “LED Traffic Signal Light With Automatic Low-Line Voltage Compensating Circuit”. Therein disclosed is a traffic light or signal using LED lights with a voltage compensating circuit that disables or re-engages a first and then a second set of LEDs in a traffic light as the input power voltage drops below a first and then a second threshold voltage. This results in the remaining LEDs being driven by an increased current, resulting in a greater light intensity.
While these prior patents disclose enhancements to LED traffic lights, there is a continuing need to improve LED traffic lights so as to be more visible and to conserve power. Additionally, there is a strong safety concern to develop a signal light that can function even during interruptions in line voltage or power.
The present invention relates to a traffic light that is self contained and utilizes both natural light and artificial light for efficiently illuminating traffic signals that have the capability of operating with little electrical power and independently during blackouts or when external power is not available. Collected natural light is time modulated and routed to a plurality of color separator switches, one color separator switch is used for each bank of signal lights on each side of the traffic light. The color separator switch divides the time modulated natural light into time modulated separate colors of red, amber or yellow, and green, which are directed to the respective signal lights with fiber optics. A sensor detects when sufficient natural light is not available and causes independent light emitting diode lights to be used in lighting the traffic signals. Photovoltaic cells are used to charge a re-chargeable battery. The battery is used to provide power to the electronic systems for controlling the natural lighting portion of the traffic light and for providing power to the light emitting diodes when natural light is not available.
It is an object of the present invention to provide a traffic light that is efficient and requires substantially less power than prior traffic lights.
It is another object of the present invention to provide a traffic light that can operate during power interruptions or outages.
It is an advantage of the present invention that it is substantially self-contained.
It is another advantage of the present invention that it requires less maintenance.
It is a feature of the present invention that the natural light is time modulated so that substantially all of the illumination intensity of the natural light is utilized by each traffic signal light at a different time providing the brightest possible perceived illumination.
It is another feature of the present invention that light emitting diodes or LEDs are used.
These and other objects, advantages, and features will become more readily apparent in view of the following more detailed description.
The color separator switches 16A and 16B provide a different color to each of the different signal lights, such as the red lights 18A and 18B and the amber or yellow lights 20A and 20B and the green lights 22A and 22B. The color separator switches 16A and 16B may be any conventional color separator, such as an LCD color switch, prism, or dichroic mirror. The color separator switches 16A and 16B are coupled to a controller 24. The controller 24 is also coupled to the natural light router and switch 14 which therethrough is coupled to a light sensor 30. The controller 24 is used to properly sequence the time modulation of the natural or white light from the natural light router and switch 14 and for controlling the operation of the color separator switches 16A and 16B so that the natural or white light entering from the natural light router and switch 14 can be separated into the different colors red, amber or yellow, and green, as well as time modulating for directing the different colors to their respective signal lights for sequencing the required color signal. The rechargeable battery 26 provides power to the controller 24. The controller 24 is also coupled directly to the different colored signal lights 18A through 22B for controlling light emitting diodes that provide the illumination for the signal lights 18A–22B when natural light is not available or sufficient to provide the required intensity illumination to the signal lights 18A, 20A, 22A, and 18B, 20B, and 22B. The light sensor or detector 30 is used to determine when the natural light is insufficient, requiring the light emitting diodes or LEDs to be used. The controller 24 may also be connected through the battery 26 to an external power and traffic control 31. The external power and traffic control 31 provides external power when required during extended overcast days or when there is insufficient natural light for long periods of time, in addition to providing any traffic control signals that may be used to coordinate different traffic lights from a central location. The battery 26 may be charged by photovoltaic cells 28.
The color switches 116A, 116B, 116C, and 116D divide the natural white light into three different colors, red, amber or yellow, and green. The color switches 116A, 116B, 116C, and 116D may be liquid crystal display or LCD color switches. The three different colors are separated or modulated in time so as to provide the different colors red, amber or yellow, and green at full intensity for only a relatively short time or duration. The time separated or modulated distinct colors are split or separated for each channel or bank by a dichroic beamsplitter 117A, 117B, 117C, and 117D and directed through fiber optics to each of the respective traffic signal lights. For example, the red light signals 118A, 118B, 118C, and 118D; the amber or yellow light signals 120A, 120B, 120C, and 120D; and the green light signals 122A, 122B, 122C, and 122D. A liquid crystal display or LCD switch 119AR, 119AY, 119AG, 119BR, 119BY, 119BG, 119CR, 119CY, 119CG, 119DR, 119DY, 119DG may also be utilized to control the on and off of the different red, amber or yellow, and green colored illumination for each bank of signal lights, respectively.
The embodiment illustrated in
In this embodiment, the light amplitude or intensity is not split and the entire light amplitude or intensity is used for each light packet 238A–D. However, each light packet 238A–D has a duration of only one-quarter of the period P. The duration of each light packet may be selected so as to take advantage of a characteristic of the human eye. Generally, the human eye cannot detect flashing above about twenty Hertz. The human eye generally perceives any flashing above about twenty Hertz as a continuous illumination. Accordingly, the incoming light in this embodiment is sequentially and equally split or divided into four channels. Each of the four channels has a light packet that carries one hundred percent of the light intensity. In this way, all four channels have one hundred percent of the light intensity available, but for only one-quarter of the time. By properly selecting the duration of the light packet or its frequency, the human eye will detect a continuous illumination. If a frequency of forty Hertz is selected, each channel or light packet will result in fifty milliseconds of light, which is repeated at forty Hertz. The one hundred percent intensity at a duration of fifty milliseconds at a frequency of forty Hertz should present itself as a continuous light intensity to the human eye. Therefore, the light signal perceived by the human viewer should appear relatively bright and be steady or continuous. It is possible to optimize this frequency to establish the highest light retention to be produced.
The control selection circuit 324 may be used to selectively control the use of natural light when it is sufficient or when it is insufficient, the light emitting diodes may be used to illuminate the traffic signals in the traffic light. The control selection circuit 324 may easily be made form conventional circuits, for example field programmable gate arrays, FPGA, or application specific integrated circuits, ASIC. The software to operate the traffic light may be application specific and interface with conventional traffic light control software.
While the preferred embodiment of the present invention is related to a traffic light having three colored lights, the term traffic light or signal may include other informational displays to control vehicles, pedestrians, or other things. For example, a traffic light may be defined as any informational display to control traffic, including pedestrian traffic such as a walk, don't walk display at a cross walk, train signals, traffic information displays, and any other illuminated display.
Additionally, while the preferred embodiment of the present invention has been described with respect to a traffic light, the present invention may by embodied in any informational display having a plurality of illuminated information signals forming words or symbols to convey any desired information. For example, rather than information related to traffic signals, the present invention may be used to display any information such as news, warnings, weather, advertising, or any other information wishing to be conveyed to an individual through an illuminated display.
While several different embodiments of the present invention have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from the spirit and scope of this invention.
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|U.S. Classification||362/20, 362/293, 362/183, 362/192, 362/231, 126/600|
|International Classification||F24J2/04, F21V19/04|
|Jul 6, 2009||FPAY||Fee payment|
Year of fee payment: 4
|Oct 11, 2013||AS||Assignment|
Free format text: DECREE OF DISTRIBUTION;ASSIGNOR:ZINCONE, ROBERT;REEL/FRAME:031389/0380
Owner name: ZINCONE, IRENE, MRS, CONNECTICUT
Effective date: 20131009
|Oct 16, 2013||FPAY||Fee payment|
Year of fee payment: 8